Chapter 3 Biodiversity in the ocean and its ecosystem service In this chapter, functions of the ocean and the current status of the marine biodiversity at the global level and for water around Japan will be identified and summarized to provide prerequisites for preparation of the basic concepts for conservation and sustainable use of marine biodiversity. 1. What are the biodiversity and various fauna and flora. circulations occur there. Evaporation of water the ecosystem service? The blessings people can obtain from such from the ocean plays a major role in sustaining Ever since beginning of its primitive form, ecosystems where various organisms interact the atmosphere-to-land circulation of water. life has repeated adaptation, evolution and are called “ecosystem services.” They include Along with water, the ocean transports heat, extinction in response to various changes “provisioning services” of resources such as it mitigates drastic changes of the climate of environment on the Earth, to create the seafood and the genetic resources for medicine, through its interactions with the atmosphere, present diversity of as many as 30 million “regulating services” for stable climate and and maintains the temperature within the species4 and their associations. “Biodiversity” clean water, “cultural services” to provide acceptable range for occurrence and growth could be referred to as the “character” and recreational and mental benefits such as sea of organisms. The ocean is deeply involved in “interconnection” of life created through the bathing, and “supporting services” such as the weather around the world and the climate long history of evolution. Human being is one nutrient circulation and photosynthesis5. kinetics. There occur and grow a variety of of the species which constitute the biodiversity, Facilitation of the objectives of the Convention organisms in the ocean, and diverse ecosystems and the biodiversity provides foundation for its on Biological Diversity, or conservation and are established there. survival. sustainable use of the biodiversity requires In recent years, there is increasing attention In the Convention on Biological Diversity, understanding of the fact that there are multiple on relationship between the ocean and the “biodiversity” is defined as the variability levels of the biodiversity as mentioned above, climate change. The ocean has not only a lot of among all organisms. Included are not only and it is important to address all levels rather water but also a plenty of carbon as a “carbon “species diversity” which is occurrence of than any single level. reservoir”. Annual net primary production of various species of fauna and flora, but also marine phytoplankton would be around 50 “intra-species (genetic) diversity” which is 2. Functions of the ocean and billion tons of carbon equivalent. This would variation in a single species according to characteristics of its ecosystems be almost equal to that of terrestrial plants, and localities, etc., and “ecosystem diversity” which (1) Physical functions and blessings from the ocean is very important as a sink for carbon refers to the variety of ecosystems such as the ocean dioxide. forests, rivers, tidal flats and coral reefs, which Ocean covers an extensive part of the Human life has been closely related to the are composed of the interrelation between Earth, and large-scale horizontal and vertical ocean with multi-functions ever since the 4 Millennium Ecosystem Assessment (2005) Ecosystem and Human Well-being Vol.1. 5 Field, C. B., M. J. Behrenfeld, J. T. Randerson and P. Falkowski (1998) Primary production of the biosphere: Integrating terrestrial and oceanic components. Science 281: 237-240. 8 Marine Biodiversity Conservation Strategy Chapter 3 Biodiversity in the ocean and its ecosystem service primary producer in the ocean, and this is Approximately a half of the world’s ocean quite different from the terrestrial ecosystem is ocean flats, or flat bottoms. However, four where large plants such as trees are the major plates collide to each other in marine areas producer. In the ocean, turnover of the primary around the Japanese Archipelago on the eastern production occurs quickly and the material edge of the Eurasian Continent, and their circulation rate through the grazing food chain submersions have created marine trenches and and microbial food chain is high. Materials, the diverse and complex bottom topography therefore, do not stay for a long time in the with drastic changes in water depth. It is ancient times. As the quantity and quality of form of the primary producers as on land. characteristic to Japan that the majority of its human activities increase, there occurs more For example, at transition regions where exclusive economic zone is deep water, with utilization of the ocean. different ocean currents or water bodies are limited shallow water over the continental shelf Direct blessings from the ocean to human in contact, cold seawater with rich nutrients and within the inland sea and bay. beings include means for transportation, supply mixes with warm surface water to stimulate As for the average water depth around of food, water, mineral and energy, and space productions of phytoplankton and attract many Japan, the East China Sea is shallow and for recreation and mental stability. In particular, organisms of higher trophic levels in the food around 300m deep, but the Sea of Japan and unexploited energy and mineral resources have web. However, one must keep in mind that the Sea of Okhotsk are about 1700m deep, and been recently identified in the ocean through the status of ecosystems changes drastically the Pacific Ocean is around 4200m deep8. A Chapter 3 various surveys and researches on the ocean. with changes of physicochemical conditions. relatively gentle continental shelf of 0 to 200m When such resources are utilized, efforts have For instance, environmental changes due to deep extends out from the continent in the East to be made to accomplish their sustainable the global-scale climate change, such as the China Sea southwest to the line between the development, and to establish and maintain an regime shift with intervals of several decades Korean Peninsula and the Noto Peninsula and ecosystem service the ocean and its Biodiversity in international order on the use of energy and and El Niño and La Niña, significantly alter in water west to Hokkaido and coastal water of mineral resources. productions and distributions of organisms. the Sea of Okhotsk. On the Pacific side, there Approximately 230 thousand species6 have are very steep bottom topographies down to (2) Characteristics of marine ecosystems been identified for marine organisms, but the depth of 4,000 to 6,000m, such as the Japan Important in consideration on the marine our knowledge on marine species is limited Trench and the Izu-Ogasawara Trench running environment and the ecosystems there is the compared to terrestrial ones. Many new species south from Honshu and the Nansei Islands existence of an extensive water body. In the are still discovered even in shallow waters, Trench (Ryukyu Trench) from Kyushu to ocean, there are layers with different water and it is expected that there are many unknown Okinawa. There are also a series of seamounts flow at different depths, and organisms and species. As for higher taxa, among all of the such as the Nansei Islands Ridge (Ryukyu ecosystems distribute three-dimensionally. 35 animal phyla7, 34 of them include species Ridge) and the Izu-Ogasawara Ridge on the Plants with photosynthesis as primary occurring in the ocean, and 16 phyla are found Pacific side. There are relatively wide undersea producers occur in photic zones down to about only in the ocean. It could be said that there are basins at the depth of about 2,000m, such as the 200m from the water surface, and on sea more morphological variations among marine Japan Basin in the Sea of Japan and the Kuril bottoms of the shallow coastal water. There organisms than terrestrial ones. Basin in the Sea of Okhotsk. occur completely different ecosystems in the Diverse environment is created in Japanese deep sea. (3) Characteristics of the marine environment water due to many warm and cold currents In the ocean, many organisms migrate for and ecosystems around Japan such as the Kuroshio Current (warm current) a long distance during their life history. In Japan is surrounded on its four sides by the addition, water, or where they occur and grow, Pacific Ocean, the East China Sea, the Sea also moves around. These lead to very high of Japan and the Sea of Okhotsk. Consisting mobility of organisms. In other words, there is of approximately 6,000 islands including a highly continuous space from the polar region Hokkaido, Honshu, Shikoku, Kyushu and to the tropics, and complex interactions among Okinawa, Japan has one of the world’s widest organisms exist over a wide area. closed sea and exclusive economic zone of Microscopic phytoplankton is the major approximately 4.47 million km2 around it. 6 Fujikura et al, (2010) Marine Biodiversity in Japanese Waters. PLoS ONE 7 According to the classification by The Union of Japanese Societies for Systematic Biology 8 National Institutes of Natural Sciences, National Astronomical Observatory of Japan (2009) Chronological Scientific Tables 2010 Marine Biodiversity Conservation Strategy 9 and the Oyashio Current (cold current) flowing rich in biodiversity. For example, the “intertidal water, coastal ecosystems maintain habitats and along Japan, and the Japanese Archipelago of zone” between the high tide and low tide lines environment for organisms, and they contribute numerous islands extending from the south to repeatedly emerges and submerges with the significantly to the protection of biodiversity. north with a wide range of climate zones from tidal rhythm. Duration of time under seawater Under unique environments such as the deep subarctic to tropical ones. In the north, drift ice varies depending on the height to produce sea and the hydrothermal vent, there occur covers the Sea of Okhotsk in winter, and unique differences in environmental factors such as organisms completely different from those in habitat and environment are created by sea ice.